Diagnosis and differential diagnosis

IgA nephropathy diagnosis must have a renal biopsy pathology, immunofluorescence or immunohistochemical results must be supported. For the vast majority of cases, the diagnosis of IgA nephropathy is not difficult. However, in some of the following cases still need to pay attention to differential diagnosis. IgA deposition in the glomerular mesangium is also associated with a variety of other diseases, IgA deposition is often accidentally discovered, its pathogenesis or clinical significance is unclear. IgA nephropathy is a common disease, so he can exist with other glomerular diseases.

1. Identification of HSPN and HSPN HSPN and IgAN are variations of the same pathological process but contribute to the systemic activation of IgA-containing immune complexes in HSP or to the local activation of IgA-containing immune complexes in IgAN Not yet determined. Purpuric nephritis is a secondary IgA nephropathy, the basic pathological features of small blood vessels inflammatory lesions, that is usually visible in the perivascular infiltration of white blood cells and nuclear debris, immunofluorescence staining confirmed involvement of the vascular wall with IgA deposition. However, when no joint pain, rash and fever, abdominal pain and other systemic symptoms, and sometimes it is indeed difficult to identify HSPN and IgAN. HSPN and IgAN have some slight differences, but not specific. Immunofluorescence changes the deposition of cellulose in HSPN. In HSPN glomeruli, many cell / fibrocytic crescents can be seen under light microscope, Glomerular necrosis or sclerosis is more common. A small number of cases can be seen in endothelial cell proliferation. Electron microscopy of HSPN can be seen subendothelial or subepithelial bulk electron dense material, and IgAN more common in the mesangial area.

2. Hypertension Renal arteriosclerosis in some patients with clinical manifestations of hypertension and renal dysfunction, renal biopsy can help distinguish between the causal relationship between the two diagnosis. Individual cases, especially immunofluorescence IgA deposition is weak, is the diagnosis of benign or malignant renal arteriosclerosis, or diagnosis of IgA nephropathy caused by renal parenchymal hypertension should be particularly careful, because further treatment and prognosis of patients with different prognosis of. Family history of hypertension, ultrasonography results will help the final diagnosis, a small number of patients even have to wait until the follow-up period of time to final diagnosis.

3. Minimal lesions For most clinical manifestations of nephrotic syndrome in patients with IgA nephropathy, leading to nephrotic syndrome is the cause of IgA nephropathy itself, but there are a small number of patients with nephrotic syndrome despite immunofluorescence IgA deposition, but the renal pathology light microscopy performance only For mild lesions, electron microscopy suggest extensive foot epithelial cell fusion, clinical response to hormone therapy, these patients should be considered the diagnosis of IgA nephropathy with minimal change, the prognosis was significantly better than pure IgA nephropathy caused by nephrotic syndrome in patients.

4. Crescentic glomerulonephritis a small number of patients with clinical manifestations of acute nephritis nephritis syndrome, pathology prompted crescentic glomerulonephritis, immunofluorescence to IgA deposition-based diagnosis should be considered type II crescentic glomerulonephritis, IgA nephropathy V Grade, anti-GBM antibodies and ANCA examination help to exclude other types of crescentic glomerulonephritis.

5 hepatitis B-associated glomerulonephritis and IgA nephropathy diagnosis can sometimes be tied, a small number of hepatitis B patients with renal pathology can be expressed as mesangial proliferative glomerulonephritis, immunofluorescence to IgA deposition, but also with hepatitis B surface antigen Or C antigen deposition in the kidney, the diagnosis should be tied for both. On the contrary some patients with IgA nephropathy, although there may be hepatitis B surface antigen or C antigen deposition in the renal pathological tissue, but if the blood markers of hepatitis B negative, the diagnosis is still IgA nephropathy.

6. Diabetic patients with diabetic nephropathy When diabetic patients with proteinuria, hematuria and the course of the disease is too short or no obvious changes in the fundus, should be considered a clear diagnosis of renal biopsy. There are three possible diagnosis of such patients, 1. Diabetic nephropathy; 2. No diabetic nephropathy, but chronic glomerulonephritis; 3. Diabetic nephropathy with chronic glomerulonephritis. Data from Korea and Hong Kong, and our own data show that diabetic patients with chronic glomerulonephritis with IgA nephropathy in the most common, accounting for more than 50%. Therefore, IgA nephropathy can be in diabetes, especially in patients with type 2 diabetes appear.

Lupus nephritis in patients with systemic lupus erythematosus, immunofluorescence results are not typical of the full house light, but mainly to IgA deposition, light microscopy showed mesangial proliferative glomerulonephritis, renal pathological diagnosis at this time should Consider IgAN, not LNI / II.